Event notification systems are often deployed in buildings, factories, shops, and other locations to provide announcements and/or warnings to individuals within the premises. Examples of event notification systems include fire alarms, tornado warning systems, earthquake alert systems, amber alert systems, hurricane warning systems, Public Address (PA) systems, and so on. Emergency alert systems are designed to disseminate information to individuals within the premises such that they have a chance to escape or find appropriate shelter or take appropriate action depending upon the nature of the emergency. The use of emergency alert systems is generally required in buildings according to local building codes. Additionally, PA systems are typically employed such that people can receive emergency and/or non-emergency related notifications. For example, in a shopping store, a clerk may request assistance at the front counter by transmitting an announcement over the PA system.
PA systems and other conventional event notification systems generally provide their announcements over strategically placed sound transmitters, for example, speakers, bells, and the like. At least one transmitter is usually located in each room of a building such that individuals in that room will receive the announcement when it is transmitted over the event notification system. The effectiveness of these event notification systems relies greatly upon whether the individuals are in a room equipped with PA speakers or bells. Additionally, the event notification system can only be effective if the individual hears the announcement.
There may be many circumstances in which an individual may be resident in a room with a PA speaker but may still fail to receive the announcement. For example, if the individual in conversing with another person over a communication device such as a phone, the individual may not necessarily hear the announcement. This is especially likely if the individuals are in a crowded and noisy conference room.
If the individual is using headphones or the like to talk on the communication device, then the probability that the individual will not receive the announcement also greatly increases. Also individuals may be sitting in a closed-door conference room from where they are not able to hear the announcement. Additionally, mechanical and/or electrical failures in the wiring of the PA system or in the PA system itself may lead to the announcement being transmitted by only a subset of all PA speakers. In this circumstance, those individuals in rooms with malfunctioning speakers will likely not receive the announcement. The failure to receive announcements can make it difficult if not impossible for individuals to react properly to the announcement. Moreover, the failure to receive an announcement related to an emergency situation may gravely impact the safety of individuals within the premises.
There have been some attempts to address these issues. As an example, television, radio, and other broadcasts are communications that can be interrupted such that an emergency notification can be transmitted. However, these types of interruptions are generally limited to one-way communications and generally cannot be applied to the bidirectional communication technology used in phones and the like.
Other solutions that do apply to bidirectional communications generally only allow one party to be interrupted on a per call basis. Transmitting event notifications to many communication devices in a short time is usually not feasible if it has to be done so one communication device at a time.
Additionally, reverse 911 solutions can provide alert notifications for persons that may be impacted by potentially hazardous or serious situations. However, this alternative leaves something to be desired because it generally only calls a subscriber database and typically does not interrupt an active phone call. Some examples can be found, for example, in U.S. Patent Application No. 2005/0083911 to Grabelsky et al. Grabelsky describes a system that provides emergency services the location of various communication devices based on the identifiers of the communication device (e.g., extension, ELIN, switch/port identifier, and/or MAC address).